Joint Research Activities

A bit of history (2006).

Coherent electron circuitry may provide that entirely new alternative. In nanocircuits the electrons can behave coherently over the circuit dimension. To achieve coherence, however, electron scattering lengths must be larger than the sample size. That demands high purity to limit impurity scattering but even limiting the thermal scattering by working at millikelvin temperatures we are still confined to circuits on the nanoscale. This provides the motivation for this application: there is an implicit imperative in nanoscience that there are enormous advantages to be gained by working at much lower temperatures. Despite the clear demand, nanoscience in general is inhibited from advancing beyond the tens of millikelvin regime by a lack of appropriate expertise and facilities. However, in Europe we already have the greatest concentration of microkelvin infrastructure and expertise in the world, developed by our quantum-fluids community. By integration and rationalization MICROKELVIN aims to put this existing infrastructure……

The Joint Research Activities in some sense form the central part of this Infrastructure Project as they contain the actual work that is going to be done. I think it is fair to say that the prime aim of the JRAs is the consolidation and enhancement of our working together. And I should emphasize that it is the input which we are supplying to make this infrastructure integration rather than the output of the integration. There are two central themes running through the JRAs. First of course the facilitating the opening up of the microkelvin temperature regime to nanoscience and other experiments which is the overall aim of the project. Secondly to enhance the teams abilities to deliver these aspirations by developing techniques, methodologies and instrumentation to achieve the main aim, both in the context of the access offering infrastructure and to the wider scientific community.

We are going to have individual talks on each of these JRAs and here I am only trying to give an overview. Let us start with JRA1 which is central to the whole activity of the project. Opening the microkelvin regime to nanoscience Which is what the whole thing is about. This project embodies the central integrating activity of this project.

The three tasks envisaged are:

1.The improvement of making thermal contact to nanosamples - to get them cooled to around or below 1 mK (Coordinator ULANC). 2.Building with our SME partner BlueFors a self-standing dilution refrigerator with nuclear and nanosample stage which can be used in any lab in the world without the need for an infrastructure to supply liquid refrigerants (thus building on task 1). (Coordinators CNRS TKK) 3.And finally with the knowledge we now have and will gain over the project the building at Lancaster of the most advanced refrigerator for microkelvin measurements which we have the collective knowledge to make. (Coordinator ULANC).

It is salutary that this knowledge is really needed now, and cannot wait for the slow grinding of the FP7 machine. As a result of just writing this proposal we have already had a major new meeting of minds between ourselves at Lancaster and Basel group with very fruitful visits in both directions in the last few months.

Since we are talking about the details of these projects in subsequent talks let me give here rather the politics and manpower aspects of what these tasks entail. Task 1 New facilitating technology for nanoscience at microkelvin temperatures. The partners involved in that are ULANC, BASEL, SAS, TKK and CNRS. Those in the list with experience in this field are ULANC, RHUL, SAS, TKK and CNRS – all having learned it through experiments on quantum fluids which means we can only work at 1 mK or below. The other partners in the consortium (HEID, SNS, BASEL, DELFT, BLUEFORS, UL, PTB) are those wanting this technology for nanoscience experiments, directly, now. But of course the other partners also want this technology for nanoscience experiments for current and future developments. So in this task the knowledge pull and the knowledge push are very clear.

Task 2 Designing a compact dilution refrigerator with a nuclear stage which can be used anywhere. The groups involved in this are (CNRS, TKK, ULANC, RHUL, BASEL, BLUEFORS and UL). All of these groups have knowhow (and will have more generated in task 1) for contributing to this project. So our work here is mostly input. The beneficiaries are European and other scientists further afield who will be able to make use of such machines in environments with poor infrastructures and lack of access to liquid helium and liquid nitrogen. This benefits peripheral parts of Europe as well as the second and third worlds. However, looking further ahead with increasing industrial demand on the world helium supply, the day is not far off when liquid helium will no longer be available and at that point (maybe closer than we think) we will all need this technology.

Our final task (3) is the creation of the worlds best system given knowledge which we already have and which we will gain in these JRAs is being prepared in Lancaster. For experiments at the lowest possible temperatures the centres which know how to do this are either represented in this room today, or are in Japan. We thus have here most of the worlds expertise in this project and it is a new venture for us as a panEuropean group to cooperate (rather than compete) in building the worlds best machine.

JRA2 Ultralow Temperature Nanorefrigerator (TKK, CNRS, RHUL, SNS, BASEL, DELFT) This is something completely different – the development of the refrigerator on a chip. This owes nothing to existing conventional cooling methods but relies on the manipulation of temperature by playing with the electron gases in various materials and manipulating them with various valves and filters. So this is in a sense an advanced version of the Peltier cooling systems. Furthermore TKK is the world leader in this technology. The advantages here is that the whole refrigerator is itself a nano-object and can in principle be incorporated in a miniaturized circuit, with obvious advantages for running components at temperatures where noise and decoherence is at a minimum.

JRA3 Attacking Fundamental Physics Problems with Microkelvin Condensed Matter Experiments. This is the one blue-skies part of this programme. The central part is the use of quantum fluids at microkelvin temperatures as models for other things in physics and especially in cosmology, because as we all know the inner structure of the helium-3 condensate resembles very closely the inner structure of space-time itself. We are thus here providing a collective service to the rest of physics and especially to cosmology. Historically, it is this subject which first put into train the working together of the three central laboratories in this project CNRS, TKK and ULANC and which has since grown to the realization of our MICROKELVIN project today. Anyway, Henri, CNRS, will be taking about that later.

JRA4 Novel Methods and Devices for Ultralow Temperature Measurements. To develop contactless measurement techniques for microkelvin temperatures To develop low noise SQUID-amplifiers for measurements at the quantum limit To develop novel ultra low temperature thermometers In other words this is the critical instrumentation activity of this project.

Thus to summarise: JRA1 The development of new macroscopic cooling methods, both for the benefit of our own integration AND for the wider community, both scientific and industrial. JRA2 The development of new microscopic cooling methods, clearly to our own benefit but of great scientific and economic implications for the wider community. JRA3 The use of our microkelvin infrastructure as a resource for tabletop cosmological, high energy and exotic particle experiments. JRA4 The development of the necessary instrumentation to support the other integrating activities (and which inter alia will necessarily have wider implications for other workers in these areas).

The End

(But its really only the beginning!